1. Field of the Invention
The present invention generally relates to an information processing apparatus and, more particularly, to an information processing apparatus which concurrently processes code information and pattern information.
2. Description of the Related Art
FIG. 1 shows a conventional information processing apparatus used as a part of an office automation system. The information processing apparatus shown in FIG. 1 comprises a computation control unit 1, a keyboard 2, a mouse 3, a display unit 4, an external memory apparatus 5 and a printer 6. The computation control unit 1 is comprised of a personal computer or an end terminal unit of a UNIX system. The keyboard is used for inputting information from an operator. The mouse is used as a pointing device. The display apparatus 4 comprises a screen such as a cathode ray tube (CRT) to display input information or a result of processing. The external memory apparatus 5 comprises a floppy disk drive (FDD), a hard disk drive (HDD) or a magneto-optical (MO) disk drive so as to record information therein. The printer 6 prints a result of processing onto a recording sheet.
The computation control unit 1 comprises, as shown in FIG. 2, a central processing unit (CPU) 11, a memory unit 12, a font unit 13, and various drivers 14-18. The CPU 11 controls an entire operation of the computation control apparatus 1. The memory unit 12 comprises a memory for storing an operation system (OS) program or an application program for operating the CPU 11 and a memory used as a working area for the CPU 11. The font unit 13 stores font information used for converting code information into image information. The driver 14 controls communications with the keyboard 2 and the mouse 3. The driver 15 controls communications with the display unit 4. The driver unit 16 controls communications with the external memory unit 5. The driver 17 controls communications with the printer 6. The driver 18 controls communications with an external apparatus (terminal) which is connected via a network such as a local area network (LAN).
An early data processing system (computation control apparatus) had a simple structure such as described above since operations to be performed were simple. Additionally, the above-mentioned conventional structure of the computation control apparatus was sufficient since most of the early computation control apparatuses were operated as closed systems, that is, most of the computation control apparatus were operated as stand-alone systems.
However, in recent years, a need for processing pattern information (image information) has drastically increased as has a need for processing code information. This is because the information processing apparatus is used for processing pattern information such as audio information and video information such as those processed in a multi-media system. Additionally, a need for background processing, which is to be performed concurrently with processing of a main job, is increased. This requires multi-task processing. Accordingly, the conventional structure of the hardware and software of the information processing apparatus should be changed to more efficiently process the information including both the code information and the pattern information.
In order to process the code information and the pattern information, a conventional computation control apparatus 20 shown in FIG. 3 has a complex structure. That is, the computation control apparatus 20 comprises, further to the computation control apparatus 1 shown in FIG. 2, an image editing unit 21, a compressing/extending unit 22, a drawing unit 23, an optical character reader (OCR) 25 and drivers 24 and 26. The image editing unit 21 edits the image information. The compressing/extending unit 22 increases a transmission speed of the image information. The drawing unit 23 performs a drawing operation. The driver 24 receives the image information read by a scanner 7. The OCR 25 converts the image information received by the scanner into code information. The driver 26 comprises a modem to control communications with external apparatuses via a telephone line. Additionally, the CPU 11 of this apparatus further has a function to read and process image information and audio information from new media such as a CD-ROM.
That is, the computation control apparatus 20 performs processing of both the code information and the pattern information which requires a high processing speed. Additionally, a high reliability is required as the apparatus becomes more complex.
Accordingly, in the information processing apparatus having the above-mentioned structure, the concurrent processing of the code information and the pattern information has become a serious problem since the capability of the apparatus for processing the code information is different from the capability required for processing the pattern information. That is, the processing system used for the code information is normally operated as a serial processing system in which a plurality of tasks in a single job are serially processed, whereas the processing system used for the pattern information is normally operated as a parallel system in which a plurality of tasks are concurrently processed. Thus, the processing of the pattern information requires a greater capability of the CPU than that of the code information. Additionally, the size of a data bus used for the code information processing system can be much less than the size of a data bus for the pattern information processing system. Accordingly, if the code information is processed by the same processing system as the processing system used for the pattern information, the processing system has too much capacity for processing the code information. Thus, a CPU having an unnecessarily large capability must be used when both methods of processing are performed by a single CPU.
For example, if the code information such as command information and the pattern information such as audio information are processed by the same CPU, there may be a problem that processing the audio information is interrupted when the code information is processed. For example, in a case where the code information is processed as a main job and the audio information is processed as background music, the processing of the background music must be interrupted while the code information is processed. The interruption may last for a very short period of time, but it may be recognizable by the user.
Additionally, it has been suggested that file data having code information be added to the front end of the pattern information as shown in FIG. 4. This kind of data format has been suggested in Japanese Laid-Open Patent Application No.5-303596 filed by the present applicant. The file of information shown in FIG. 4 has a sub-data area and a main-data area. The sub-data area contains only code information and the main-data area contains the pattern information. The code information in the sub-data area is used for controlling the processing of the pattern information in the main-data area. When the file data of this kind is processed, input data input from the external apparatus to the computation control apparatus contains both the code information and the pattern information. In the conventional computation control apparatus, the code information and the pattern information are processed by the same CPU. Accordingly, the capability of the CPU must be determined to have such a capacity sufficient to process the pattern information. Thus, the capability of the CPU is larger than necessary for processing the code information.